After iOS 12 beta 9, Apple released the eighth beta version of macOS 10.14 Mojave, tvOS 12 and watchOS 5. To install the updates, you need a developer account registered with the Apple Developer Program.
watchOS 5 beta 8 should be downloaded via Wi-Fi via the iPhone your watch is paired with: Apple Watch should be at least 50% charged during the update and the iPhone has the latest beta version of iOS 12. To install tvOS 12 beta 8, go to "Settings" → "General" → "Software Updates" and the beta version of macOS 10.14 can be downloaded to the Mac App Store.
At the time of writing, the notes do not know what's new in these updates. They are probably aimed at increasing the stability of the system and correcting errors, but if we notice any changes in them, we will quickly tell you about them.